This invention relates generally to papers which, for example, are suitable for various printing processes, and more specifically the present invention is directed to size press treated plain papers and the use of these papers in ink jet printing processes, dot matrix and impact printers, gravure printing systems, xerographic imaging and thermal transfer printing processes. In one embodiment, the present invention relates to papers comprised of a supporting substrate surface treated preferably on a size press, a known apparatus used to coat or treat the paper during the drying process in a paper machine or a coating apparatus, such as a Dilts Coater, with a mixture of starch or other similar component, such as gelatin, with certain desizing agents including hydrophilic poly(dimethyl siloxanes); poly(alkylene glycol), the derivatives thereof, poly(propylene oxide)-poly(ethylene oxide) copolymers; fatty ester modified compounds of phosphate, sorbitan, glycerol, poly(ethylene glycol), sulfosuccinic acid, sulfonic acid, alkyl amine; poly(oxyalkylene) modified compounds of sorbitan esters, fatty amines, castor oil, fatty acid, fatty alcohol; quaternary alkosulfate compounds; fatty imidazolines,; and the like. In one embodiment of the present invention, the fibers in the surface treated papers are coated with the aforementioned materials thereby reducing the levels of internal sizing and enabling, for example, these fibers to accept ink compositions with minimum spreading thereof thus preventing or minimizing wicking, a major source of undesirable print edge raggedness. The desizing components can also be applied to paper fibers on a known coater from aqueous or alcohol solutions. The aforementioned treatments can be modified as indicated herein preferably to optimize the selection of these papers for use in liquid ink printing to improve print through, which modification can be accomplished by the addition of a binder polymer such as hydroxypropylmethyl cellulose, hydroxyethyl cellulose and the like.
Paper is often sized with sizing components for the purpose of retarding or preventing penetration of liquids into the structure. This is commonly done by introducing. The acid sizing chemicals, such as Mon size available from Monsanto Chemical Company or alkaline sizing chemicals such as Hercon-76 available from Hercules Company, are precipitated onto the fibers primarily for the purpose of controlling penetration of liquids into the final dry paper. This process is known as internal sizing. Surface sizing involves the application of dispersions of film-forming substances such as converted starches, gums and modified polymers to previously formed paper. Surface sizing imparts strength to the paper and thus high quality printing papers are often surface sized as well. These internally and surface sized papers, when used to print graphics or checkerboard color patterns with an ink jet printer containing predominantly water based inks, such as for example those inks selected for the Xerox Corporation 4020.TM. color ink jet printer, yield images which have undesirable pronounced inter-color bleed in most instances (high edge-raggedness). The extent of inter-color bleed is reduced slightly with papers which are internally sized and no surface sizing. However, in general, these papers usually possess undesirable adequate mechanical strength, and can exhibit enhanced print through. In conventional paper with no surface sizing but with different levels of internal sizing, the intercolor bleed of the ink jet images can be lowered with decreasing sizing, while the print through continues increasing and becomes unacceptable.
One of the objectives of the present invention is to enable a rapid drying plain ink jet paper with substantially no print through and intercolor bleed values equivalent to a paper with no internal or external sizing. This objective can be attained by, for example, treating sized papers with desizing agents which penetrate into the paper, lift the sizing from the fibers and rearrange the sizing material in the bulk of the paper which assists in overcoming print through problems. The desizing agents can be applied on a known coater to substantially any commercially available paper and thereby convert it to an ink jet paper. This treatment can also be effected to an internally sized paper at the size press by incorporating the desizing agent into starch or any other similar binder material.
In a patentability search report the following United States patents were recited: U.S. Pat. No. 4,478,682, the disclosure of which is totally incorporated herein by reference, which illustrates a method for sizing paper wherein a sizing agent and a sizing accelerator, such as the reaction product of a water soluble polyaminopolyamide, including one derived from the reaction of adipic acid and diethylene triamine, an epihalohydrin, such as epichlorohydrin, bis(hexamethylene)triamine, or polyethylene polyamines is selected; U.S. Pat. No. 4,198,269 which discloses quaternary ammonium salts of epihalohydrin polymers as fiber treating materials, examples of polymers including water soluble polymers with a predominantly polyalkyleneoxy backbone containing ammonium salt groups; U.S. Pat. No. 4,279,794 directed to a sizing composition comprised of a sizing component and an accelerator of a poly(diallylamine)epihalohydrin resin; also note the disclosure of polyaminopolyamide derived from adipic acid and diethylene triamine at column 11, lines 62 to 64; and U.S. Pat. No. 3,520,774 relating to an epihalohydrin-polyethylene amine additive for paper.
There are disclosed in U.S. Pat. No. 4,022,634 papers with internal sizing compositions comprising an aqueous mixture of ammonia, an ammonium salt, and a rosin that is modified with from about 5 to 50 percent based on the weight of the rosin of an organic acidic compound selected from the group consisting of an .alpha., .beta.-unsaturated organic acid, an anhydride thereof, and mixtures thereof. In one embodiment, the ammonia and ammonium salt are produced by the reaction product of a urea and an acid selected from the group consisting of sulfamic acid, phosphoric acid, oxalic acid, methane-sulfonic acid, trichloroacetic acid, nitric acid, sulfuric acid, hydrochloric acid, stearic acid, and acetic acid.
In U.S. Pat. No. 4,152,312 there are described anionic sizes for paper or a paper-like material. Substantially equimolecular copolymers of maleic acid anhydride and diisobutylene are esterified to form the corresponding semi-esters. From 10 to 100 mol percent of the anhydride groups are reacted with an aliphatic or cycloaliphatic alcohol, and at least 50 mol percent of the formed carboxylic groups are neutralized with alkali, ammonia or aliphatic amines according to the teachings of this patent in an embodiment thereof.
Further, there is disclosed in U.S. Pat. No. 4,335,184 a recording paper with improved image quality, comprising a base paper, the pH of its cold water extract being 5.0 to 10.0, and disposed thereon a coating layer containing a saponified-type petroleum resin sizing agent.
There is disclosed in U.S. Pat. No. 4,481,244 a material for writing or printing, which comprises a substrate and a coating layer formed thereon of a material containing a polymer having both hydrophilic segments and hydrophobic segments.
Also, there is illustrated in U.S. Pat. No. 4,657,946 cationically charged water soluble vinyl addition polymers and condensation polymers which provide improved emulsification of alkanyl succinic anhydride sizing agents. Sized paper products prepared from alkanyl succinic anhydride emulsions obtained with the polymers disclosed have superior ink holdout according to the teachings of this patent.
Disclosed in the U.S. Pat. No. 4,740,420 is a recording medium for ink jet printing comprising a support material containing at least in the surface portion thereof a water-soluble metal salt with the ion valence of the metal thereof being 2 to 4 and a cationic organic material.
Further, there is disclosed in U.S. Pat. No. 4,784,727 a paper with sizing agent which contains from 1 to 60 parts by weight of a fixing and sizing accelerating agent and from 0 to 80 parts by weight of conventional auxiliaries per 10 parts by weight of hydrophobic, cellulose-reactive sizing materials, the fixing and sizing accelerating agent being a polymer composed of linear or branched carbon chains to which primary, secondary or tertiary amino and/or quaternary ammonium groups are bound directly or by side chains.
Additionally, there is disclosed in U.S. Pat. No. 4,810,301 an internal size composition with a sizing agent comprising, for example, (1) 70 to 99.9 weight percent of a substituted alkyl succinic anhydride or a substituted alkanyl succinic anhydride or a mixture thereof, and (b) 0.1 to 30 weight percent of phosphates of polyoxyethylene alkyl ether esters or phosphates of polyoxyethylene alkyl aryl ether esters and a process of using this composition for the preparation of papers by dispersing the composition, adding the resulting aqueous dispersion to a pulp slurry or paper making material.
Moreover, there is disclosed in U.S. Pat. No. 4,425,405 an ink jet recording sheet comprising a paper support applied on at least one surface thereof or internally a composition which comprises an aqueous dispersion of poly(vinylpyrrolidone), vinylpyrrolidone-vinyl acetate copolymer or a mixture thereof serving as a binder or sizing agent and a white filler. The white filler can be contained in a binder weight ratio of 10:1 to 0.2:1 when the composition is applied on the surface of the paper support. When the composition is internally incorporated in the recording sheet, it can comprise 10 to 60 parts by weight of the filler and 2 to 20 parts by weight of the binder per 100 parts by weight of pulp.
Further, there is disclosed in U.S. Pat. No. 4,554,181 an ink jet recording sheet with a recording surface which includes a combination of a water soluble polyvalent metal salt and a cationic polymer, said polymer having cationic groups which are available in the recording surface for insolubilizing of an anionic dye.
The following U.S. patents are also mentioned: U.S. Pat. No. 4,701,367 relating to coatings such as styrene/butadiene/styrene triblocks for typewriter ribbon transparencies, see the Abstract of the Disclosure for example; U.S. Pat. No. 4,711,816 relating to transparent sheet materials for plain paper electrostatic imaging apparatuses, which sheets contain an image receiving layer; U.S. Pat. No. 4,783,376 relating to transparencies with a coating layer of a certain electrical resistance; and U.S. Pat. No. 4,756,961 which discloses an ink accepting coating containing particles of silica, aluminum silicate, zinc oxide, or titanium dioxide.
There are disclosed in U.S. Pat. No. 3,759,744 and U.S. Pat. No. 4,268,595 methods for the preparation of electrographic recording papers for imaging. More specifically, according to the teachings of these patents electrographic recording papers can be prepared by applying a dielectric coating on a relatively conductive sheet. Various compounds, such as salts and other compounds capable of retaining or attracting moisture in the sheet may be incorporated into the paper to enhance the conductive properties. In some recording papers the conductive layer is applied on one side of the paper and the dielectric is applied to the other side. Also, the dielectric layer can be applied over the conductive layer. Other conventional recording papers comprise an electrically conductive layer and a dielectric layer thereon on one surface of a base paper and an electrically conductive layer on the outer surface of the base paper. Materials selected as the dielectric layer include highly insulating resins such as silicone resins, epoxy resins, poly(vinyl acetate) resins, vinyl acetate resins, vinyl chloride resins and styrene-butadiene copolymers. These resins are generally dissolved in an organic solvent and coated on the base paper. It is usually necessary to provide an undercoat layer as a barrier coating on a base paper prior to the coating of a solution of an organic solvent type resin to prevent penetration of the solvent used into the paper. Examples of other electrographic papers are prepared by applying a dielectric film of plastic material such as poly(ethylene) or poly(styrene) to the paper surface by melt extrusion. Also disclosed in U.S. Pat. Nos. 3,011,918; 3,264,137; 3,348,970 and 3,110,621 are papers for electrostatic recording employing aqueous coatings both for the dielectric layer as well as the conductive layer. The materials of the conductive layer can be water soluble or dispersable vinyl benzyl quaternary ammonium compounds and the dielectric layer can be comprised of carboxylated poly(vinyl acetate) in an aqueous ammonical solution.
Also disclosed in U.S. Pat. No. 3,759,744 is an electrostatic recording paper, which paper can be prepared by applying three successive aqueous coats to a machine glazed side of a paper web. The first coating contains titanium dioxide and an electroconductive water dispersible polymer of a vinyl benzyl quaternary ammonium compound. The second coating can be comprised of oxidized starch and calcium carbonate, and the third coating may contain calcium carbonate and a carboxylated poly(vinyl acetate) in ammonical solution. The resulting web can then be dried between successive coatings and may be steam treated, see The Abstract of the Disclosure for example.
Additionally, there are disclosed in U.S. Pat. No. 3,790,435 and U.S. Pat. No. 4,318,950 synthetic papers and methods for the preparation thereof. The term synthetic paper as indicated on page 1, line 20, of U.S. Pat. No. 4,318,950 refers to a paper like laminar structure in the form of thin sheets or films of synthetic resinous material, which papers can be employed in writing or printing processes. Disclosed in U.S. Pat. No. 3,380,868 are oriented thermoplastic film laminated structures which can be selected for various imaging processes. Polymeric film structures having a matte finish and a cellular structure achieved with the addition of fillers which roughens the surface upon stretching of the films and renders them receptive to marking by crayons, pencil and ballpoint pen are disclosed in U.S. Pat. No. 3,154,461. Laminates comprising layers of oriented films of thermoplastic materials in which at least one of the outermost layers contains a suitable inert additive are disclosed in U.S. Pat. No. 3,515,626. These laminates are useful in films which may be written on by a pencil or a crayon.
Disclosed in U.S. Pat. No. 3,790,435 are synthetic papers with acceptable foldability and comprised of a nonlaminated structure of one thermoplastic resin film or a laminated structure of at least two thermoplastic resin films, see the Abstract of the Disclosure for example. Each of the films is stretched or molecularly oriented, and one or more of the films can contain a fine inorganic filter to provide paperness of the film. According to this patent, some of the films may contain certain amounts of poly(styrene) as a foldability improving agent.
Further, in U.S. Pat. No. 4,592,954, the disclosure of which is totally incorporated herein by reference, there is illustrated a transparency for ink jet printing comprised of a supporting substrate and thereover a coating of a blend of carboxymethyl cellulose, and poly(ethylene oxide). Also, in this patent there is illustrated an ink jet paper wherein the surface coating or sizing is comprised of poly(ethylene oxide).
In U.S. Pat. No. 4,865,914, the disclosure of which is totally incorporated herein by reference, there are illustrated ink jet transparencies and ink jet papers with coatings thereover which are compatible with the inks selected for marking, and wherein the coatings enable acceptable optical density images to be obtained. More specifically, in one embodiment of the aforesaid patent there are provided coatings for ink jet paper comprised of a supporting substrate, and thereover a quaternary mixture of hydroxypropyl cellulose, carboxymethyl cellulose, poly(ethylene oxide), and colloidal silica.
In U.S. Pat. No. 5,006,407 , the disclosure of which is totally incorporated herein by reference, there are illustrated coated papers wherein the ink receiving layer is comprised of a blend with from about 10 to about 90 percent by weight of poly(ethylene oxide) and 90 to about 10 percent by weight of a component selected from the group consisting of (1) hydroxypropylmethyl cellulose; (2) vinylmethyl ether/maleic acid copolymer; (3) acrylamide/acrylic acid copolymer; (4) carboxymethylhydroxyethyl cellulose sodium salt; (5) hydroxyethyl cellulose; (6) water soluble ethylhydroxyethyl cellulose; (7) cellulose sulfate; (8) poly(vinyl alcohol); (9) poly(vinyl pyrrolidone); (10) hydroxybutylmethyl cellulose; (11) hydroxypropyl cellulose; (12) poly(2-acrylamido-2-methyl propane sulfonic acid); (13) methyl cellulose; (14) hydroxyethylmethyl cellulose; (15) poly(diethylene triamine-co-adipic acid); (16) poly(imidazoline) quaternized; (17) poly(ethylene imine) epichlorohydrin; (18) poly(N,N-dimethyl-3,5-dimethylene piperidinium chloride); or (19) ethoxylated poly(ethylene imine)
In U.S. Pat. No. 5,075,153 , the disclosure of which is totally incorporated herein by reference, there is illustrated an ink jet paper comprised of a supporting substrate, a coating and a plasticizer.
Although the papers illustrated in the prior art are suitable for their intended purposes, there remains a need for papers with new coatings that are useful in ink jet printing processes, electrophotographic imaging and printing processes, including color processes, and that will enable the formulation of images with high optical densities. Additionally, there is a need for treated papers that can be selected for ink jet color printing processes. Another need resides in providing papers the fibers of which are coated continuously with certain copolymers as illustrated herein. Further, there is a need for papers that avoid or minimize jamming at the fuser roll, thus shortening the life thereof. Also, there is a need for static-free papers, or wherein the static charge thereon is minimized or substantially avoided. Another need resides in the provision of papers for ink jet, dot matrix, typewriters and crayon printing processes, and wherein images of high optical density, such as greater than one, are obtained in some embodiments of the present invention.